By Tommy H. Thomason

Tuesday, July 24, 2012

Tailhook? We don't need no stinking tailhook...


When an aircraft carrier deploys, it departs with an air wing comprised of several specialized squadrons to provide a full offensive and defensive capability.  The exact composition of the air wing has varied over the years, but in addition to fighter and attack squadrons, there are always airborne early warning and reconnaissance airplanes as well plane guard/utility helicopters. Now electronic warfare airplanes are a standard part of the air wing.

Fighter and attack squadrons were typically assigned to a specific air wing for an extended period of time. At one point, in the late 1950s and early 1960s there were usually three fighter squadrons per air wing even though only two were required for a deployment. Because of the rapid development of new or improved fighter types at the time, one of the three was likely to be in transition to a new type and not ready to deploy.

For various reasons, a squadron might not be ready for deployment with its air wing and a substitute was required. Often, this would be a Marine Corps squadron since its pilots would all be naval aviators, qualified for carrier takeoffs and landings. VMFA-333 deployed several times, for example flying F-4s with Carrier Air Wing Eight aboard Nimitz in 1976.
 Official U.S. Navy photo via Johan A. (Hans) Engels (see http://www.thunderstreaks.com/)

One very non-traditional Marine Corps squadron deployment took place on the last cruise of Roosevelt. VMA-231, flying AV-8A Harriers, was assigned to Carrier Air Wing 19 for its cruise in the Mediterranean from October 1976 to April 1977. Also aboard were two squadrons of F-4Ns and three of A-7Bs, along with detachments of E-1Bs (for the last deployment of this type), RF-8Gs, and SH-3Gs.

In the mid 1970s, the Navy was seriously evaluating a transition to V/STOL aircraft for all sea-based, manned, tactical air missions instead of building more big aircraft carriers equipped with catapults and arresting gear. In early 1976, the CNO briefed OSD on a tentative plan to do so.  The assignment of VMA-231 to the Roosevelt’s air wing was intended to provide insight into the feasibility and benefits of a operating a V/STOL fighter/bomber at sea.

The Harrier had been in service with the Marine Corps since 1971 and had already been evaluated in an extended series of at-sea trials aboard, among others, the amphibious assault ship Guam (LPH-9) that was serving as an Interim Sea Control Ship. This resulted in the development of a corrosion control plan for an extended deployment among other operational procedures. However, there were still concerns about the Harrier’s maintenance requirements, hot exhaust, lack of endurance, etc.

VMA-231 worked up to the deployment via a series of mini-cruises aboard Franklin D. Roosevelt beginning in late June 1976. These established operating procedures and familiarized the ship’s company with the unique characteristics of the Harrier, like the downward-directed engine exhaust in VTOL mode.

 U.S. Naval Institute Proceedings October 1977

V/STOL advocates considered the experiment a virtually unqualified success. Complying with standard carrier cyclic operations (90-minute flight period for the conventional takeoff and landing airplanes) proved to be unnecessary since the Harriers could land in any open space during a launch/land cycle. Benefits demonstrated early on included no time or crew required to hook up to the catapult for takeoff, virtually no waveoffs (and zero bolters), and the ability to back into a designated parking space. The Harriers could also land with the ship steaming out of the wind in conditions that precluded the operation of its conventional airplanes.

Rolling takeoffs were a bit more problematical in some wind over deck conditions but a vertical takeoff was almost always possible. Flight time, however, was limited to 20 minutes by the reduction in fuel required.

Over 2,000 sorties and landings, 15% at night, were accomplished by VMA-231 during the deployment. There were no aircrew or aircraft losses, a non-trivial accomplishment given the accident rate of carrier operations. The promise of V/STOL seemed to have been clearly demonstrated and V/STOL aircraft welcome aboard.

In parallel with and supported by this evaluation, the Navy initiated a set of V/STOL development programs, with V/STOL A being a subsonic multi-mission aircraft and V/STOL B, a supersonic fighter and attack aircraft. (There was also a V/STOL C, which was to be a smaller ASW aircraft to replace the LAMPS Mk III helicopter operating from frigates and destroyers.)

Except for Bell's tiltrotor and Sikorsky's ABC, the V/STOL A concepts used various forms of lift fans and/or high-bypass-ratio jet engines like this Vought proposal.
The V/STOL B designs were equally innovative, in some cases using lift fans for more efficient vertical lift like this McDonnell Douglas concept.

After only a couple of years of studies, however, the Navy reversed course after completing its Sea-Based Air Master Study in 1980. It concluded that an all-V/STOL approach incorporating existing technology was high risk and in any event would cost more than utilizing conventional airplanes.

Two aircraft, the V-22 Osprey and the F-35B, did eventually result from the Navy's flirtation with V/STOL, however. The tiltrotor had been proposed for V/STOL A and thereby attracted the attention of the Marine Corps. The F-35B resulted from follow-on research programs to advance V/STOL technology. It's therefore possible that the U.S. Navy might yet transition to V/STOL carriers...

3 comments:

Anonymous said...

Still have that range and payload problem with the F-35B, although somewhat improved over the AV-8B.

Anonymous said...

Not so. An F-35B -- on internal fuel only, ~13500# of JP -- has more radius of action than a SH similarly armed and carrying a centerline drop (~17500# of JP). Internal weapons and large internal fuel capacity is not only beneficial for signature control but also for aerodynamic performance.

Anonymous said...

Came across an interesting publication that references the VTOL program, and the coordination with NASA that was involved. The publication was NASA SP-501, by W.H. Deckert and J.A.Franklin. Title was "Powered-lift Aircraft Technology". I wonder if there's any copies still floating around outside of archives or libraries.